Classified as Critically Endangered (CR) by the IUCN Red List 2007 (1). Listed on Appendix I of CITES (3) and Appendices I and II of the Convention on Migratory Species (CMS, or Bonn Convention) (4).

The Mediterranean monk seal is one of the most endangered mammals in the world (5). The description of this species by Aristotle was the first known written description of a pinniped (a group that includes seals, sea lions and walrus) (2), and the head of a monk seal appeared on one of the first ever coins, around 500 BC (5). Adults have a brown or grey coat, which becomes paler on the undersurface (2) and males often feature a white patch on the belly (5). Old males are darker in colour and often become black, but retain the ventral white patch. Newborn infants are black and woolly with a white or yellow patch on the belly, the shape of which can sometimes be used to determine the sex of an individual (2).

Once widespread throughout the Mediterranean, the Black Sea and the northwestern coast of Africa, this monk seal has suffered a devastating decline (2). It is now restricted to a handful of small and scattered colonies in the Ionian and Aegean Seas and the southern coast of Turkey in the Mediterranean, as well as scattered populations on the coasts of the western Sahara and Mauritania, and the Desertas Islands, Madeira (2). It is thought that just two of these populations are viable, in Greece and northwest Africa (6). The species has not been seen in the Black Sea for over five years (7). Although no reliable estimates of total population size exist, it is thought to number between just 400 to 500 individuals (6) (8), and is declining (7).

Usually found in coastal waters (9). Many of the traditional sandy haul-out beaches have been developed for tourism, and the species now tends to haul-out and pup in secluded, remote caves (10).

Active in the day, the Mediterranean monk seal feeds on a variety of fish and cephalopods (such as squid and octopus) (9). Individuals reach sexual maturity at five to six years of age, and mating occurs between September and November, when females haul-out in caves to give birth to a single pup that weighs between 16 and 18 kilograms (2). While the suckling time may be up to four months, the female will remain with her pup for up to three years (11). The social organisation of the Mediterranean monk seal is not known, but groups tend to form in breeding caves (2).

Mediterranean monk seals are highly sensitive to disturbance and humans have extensively used both the sea and beaches of their habitat for centuries, causing the population to collapse (2). The main threats facing this species are deliberate killing by fishermen who perceive the species as a competitor for fish, entanglement in fishing gear, disturbance and habitat loss through development and tourism, disease, and the effects of toxic algal blooms (2). In 1997, two thirds of the seals in the largest population, located at Cap Blanc, Mauritania, were lost due to the accumulation of toxins in fish following an algal bloom (5) (10). These shy creatures have taken to hauling out in caves to give birth, rather than on developed beaches, and the collapse of such caves is a further threat to the survival of the species (2).

The IUCN Species Survival Commission Seal Specialist Group has devised an Action Plan for the conservation of the species, the aims of which include the involvement of local fishermen, research into the status of the species and the development of a captive breeding programme (7). A Greek National Programme for the Protection of the Monk Seal has been established, aiming to prevent human-induced mortalities of the species and to restore and maintain a viable self-supporting population (6). Some experts believe that the removal of pups from a population, to supply a captive programme, could severely affect breeding within the wild population, and injure the pups concerned (7). Captive breeding is usually recommended for mammal species of such low numbers as this and with threats continuing in the wild, but concerns that removing young seals from the wild will not severely affect breeding in the wild and will not injure or negatively affect survival of the captured young must be adequately addressed (11). It is clear that determined action is urgently required if this reclusive, beleaguered species is to escape total extinction.